Re: [PATCH v10 17/19] dmaengine: ti: k3-udma-v2: Add support for PKTDMA V2
From: Sai Sree Kartheek Adivi
Date: Thu Oct 01 2026 - 03:19:04 EST
On 28/09/26 14:09, Vignesh Raghavendra wrote:
>> The PKTDMA V2 is different than the existing PKTDMA supported by the
>> k3-udma driver.
>>
>> The changes in PKTDMA V2 are:
>> - Autopair: There is no longer a need for PSIL pair and AUTOPAIR bit
>> needs to set in the RT_CTL register.
>> - Static channel mapping: Each channel is mapped to a single
>> peripheral.
>> - Direct IRQs: There is no INT-A and interrupt lines from DMA are
>> directly connected to GIC.
>> - Remote side configuration handled by DMA. So no need to write to
>> PEER registers to START / STOP / PAUSE / TEARDOWN.
>> - Unified Channel Space: Tx and Rx channels share a single register
>> space. Each channel index is specifically fixed in hardware as either
>> Tx or Rx in an interleaved manner.
>>
>> Signed-off-by: Sai Sree Kartheek Adivi <s-adivi@xxxxxx>
>>
>> diff --git a/drivers/dma/ti/k3-udma-common.c b/drivers/dma/ti/k3-udma-common.c
>> index 30cb8044ff10..5fa3a7b8d202 100644
>> --- a/drivers/dma/ti/k3-udma-common.c
>> +++ b/drivers/dma/ti/k3-udma-common.c
>> @@ -2465,9 +2465,16 @@ static int pktdma_setup_resources(struct udma_dev *ud)
>> ud->tchan_map = devm_bitmap_zalloc(dev, ud->tchan_cnt, GFP_KERNEL);
>> ud->tchans = devm_kcalloc(dev, ud->tchan_cnt, sizeof(*ud->tchans),
>> GFP_KERNEL);
>> - ud->rchan_map = devm_bitmap_zalloc(dev, ud->rchan_cnt, GFP_KERNEL);
>> - ud->rchans = devm_kcalloc(dev, ud->rchan_cnt, sizeof(*ud->rchans),
>> - GFP_KERNEL);
>> + if (ud->match_data->version == K3_UDMA_V1) {
>> + ud->rchan_map = devm_bitmap_zalloc(dev, ud->rchan_cnt, GFP_KERNEL);
>> + ud->rchans = devm_kcalloc(dev, ud->rchan_cnt, sizeof(*ud->rchans),
>> + GFP_KERNEL);
>> + } else {
>> + ud->rchan_map = ud->tchan_map;
>> + ud->rchans = ud->tchans;
>> + ud->chan_map = ud->tchan_map;
>> + ud->chans = ud->tchans;
>> + }
>> ud->rflow_in_use = devm_kcalloc(dev, BITS_TO_LONGS(ud->rflow_cnt),
>> sizeof(unsigned long),
>> GFP_KERNEL);
>> @@ -2566,13 +2573,21 @@ int k3_udma_setup_resources(struct udma_dev *ud)
>> }
>> break;
>> case DMA_TYPE_PKTDMA:
>> - dev_info(dev,
>> - "Channels: %d (tchan: %u, rchan: %u)\n",
>> - ch_count,
>> - ud->tchan_cnt - bitmap_weight(ud->tchan_map,
>> - ud->tchan_cnt),
>> - ud->rchan_cnt - bitmap_weight(ud->rchan_map,
>> - ud->rchan_cnt));
>> + if (ud->match_data->version == K3_UDMA_V1) {
>> + dev_info(dev,
>> + "Channels: %d (tchan: %u, rchan: %u)\n",
>> + ch_count,
>> + ud->tchan_cnt - bitmap_weight(ud->tchan_map,
>> + ud->tchan_cnt),
>> + ud->rchan_cnt - bitmap_weight(ud->rchan_map,
>> + ud->rchan_cnt));
>> + } else {
>> + dev_info(dev,
>> + "Channels: %d (tchan + rchan: %u)\n",
>> + ch_count,
>> + ud->chan_cnt - bitmap_weight(ud->chan_map,
>> + ud->chan_cnt));
>> + }
>> break;
>> default:
>> break;
>> diff --git a/drivers/dma/ti/k3-udma-glue.c b/drivers/dma/ti/k3-udma-glue.c
>> index 70eaf7ee57e6..996c130b10f4 100644
>> --- a/drivers/dma/ti/k3-udma-glue.c
>> +++ b/drivers/dma/ti/k3-udma-glue.c
>> @@ -166,6 +166,29 @@ static int of_k3_udma_glue_parse_chn(struct device_node *chn_np,
>> goto out_put_spec;
>>
>> thread_id = dma_spec.args[0];
>> +
>> + /*
>> + * V2 PKTDMA DT specifiers encode the hardware flow/channel ID in
>> + * args[0] rather than the PSI-L thread ID used by V1. Resolve the
>> + * PSI-L thread ID before the common path checks the direction bit.
>> + */
>> + if (common->udmax->match_data->version == K3_UDMA_V2 &&
>> + xudma_is_pktdma(common->udmax)) {
>> + struct psil_endpoint_config *ep_cfg;
>> + u32 psil_thread_id;
>> + bool dev_to_mem;
>> +
>> + ep_cfg = psil_get_ep_config_by_id(thread_id, true,
>> + &psil_thread_id, &dev_to_mem);
>> + if (IS_ERR(ep_cfg)) {
>> + dev_err(common->dev,
>> + "No PSI-L config for flow %u\n", thread_id);
>> + ret = PTR_ERR(ep_cfg);
>> + goto out_put_spec;
>> + }
>> + thread_id = psil_thread_id;
>> + }
>> +
>> if (dma_spec.args_count == 2) {
>> if (dma_spec.args[1] > 2 && !xudma_is_pktdma(common->udmax)) {
>> dev_err(common->dev, "Invalid channel atype: %u\n",
>> diff --git a/drivers/dma/ti/k3-udma-private.c b/drivers/dma/ti/k3-udma-private.c
>> index 44c097fff5ee..525155d3bb51 100644
>> --- a/drivers/dma/ti/k3-udma-private.c
>> +++ b/drivers/dma/ti/k3-udma-private.c
>> @@ -174,16 +174,30 @@ EXPORT_SYMBOL(xudma_is_pktdma);
>>
>> int xudma_pktdma_tflow_get_irq(struct udma_dev *ud, int udma_tflow_id)
>> {
>> - const struct udma_oes_offsets *oes = &ud->soc_data->oes;
>> + if (ud->match_data->version == K3_UDMA_V1) {
>> + const struct udma_oes_offsets *oes = &ud->soc_data->oes;
>>
>> - return msi_get_virq(ud->dev, udma_tflow_id + oes->pktdma_tchan_flow);
>> + return msi_get_virq(ud->dev, udma_tflow_id + oes->pktdma_tchan_flow);
>> + }
>> + struct platform_device *pdev = to_platform_device(ud->dev);
>> + char irq_name[10];
>> +
>> + snprintf(irq_name, sizeof(irq_name), "tx-%u", udma_tflow_id);
>> + return platform_get_irq_byname(pdev, irq_name);
>> }
>> EXPORT_SYMBOL(xudma_pktdma_tflow_get_irq);
>>
>> int xudma_pktdma_rflow_get_irq(struct udma_dev *ud, int udma_rflow_id)
>> {
>> - const struct udma_oes_offsets *oes = &ud->soc_data->oes;
>> + if (ud->match_data->version == K3_UDMA_V1) {
>> + const struct udma_oes_offsets *oes = &ud->soc_data->oes;
>> +
>> + return msi_get_virq(ud->dev, udma_rflow_id + oes->pktdma_rchan_flow);
>> + }
>> + struct platform_device *pdev = to_platform_device(ud->dev);
>> + char irq_name[10];
>>
>> - return msi_get_virq(ud->dev, udma_rflow_id + oes->pktdma_rchan_flow);
>> + snprintf(irq_name, sizeof(irq_name), "rx-%u", udma_rflow_id);
>> + return platform_get_irq_byname(pdev, irq_name);
>> }
>> EXPORT_SYMBOL(xudma_pktdma_rflow_get_irq);
>> diff --git a/drivers/dma/ti/k3-udma-v2.c b/drivers/dma/ti/k3-udma-v2.c
>> index ba3042e866ca..a71471aa7707 100644
>> --- a/drivers/dma/ti/k3-udma-v2.c
>> +++ b/drivers/dma/ti/k3-udma-v2.c
>> @@ -578,7 +578,7 @@ static int udma_v2_alloc_rx_resources(struct udma_chan *uc)
>>
>> rflow = uc->rflow;
>> if (ud->tflow_cnt)
>> - fd_ring_id = ud->tflow_cnt + rflow->id;
>> + fd_ring_id = rflow->id;
>> else
>> fd_ring_id = uc->rchan->id;
>> ret = k3_ringacc_request_rings_pair(ud->ringacc, fd_ring_id, -1,
>> @@ -770,6 +770,148 @@ static int bcdma_v2_alloc_chan_resources(struct dma_chan *chan)
>> return ret;
>> }
>>
>> +static int pktdma_v2_alloc_chan_resources(struct dma_chan *chan)
>> +{
>> + struct udma_chan *uc = to_udma_chan(chan);
>> + struct udma_dev *ud = to_udma_dev(chan->device);
>> + struct platform_device *pdev = to_platform_device(ud->dev);
>> + char irq_name[10];
>> + u32 irq_ring_idx;
>> + int ret;
>> +
>> + /*
>> + * Make sure that the completion is in a known state:
>> + * No teardown, the channel is idle
>> + */
>> + reinit_completion(&uc->teardown_completed);
>> + complete_all(&uc->teardown_completed);
>> + uc->state = UDMA_CHAN_IS_IDLE;
>> +
>> + switch (uc->config.dir) {
>> + case DMA_MEM_TO_DEV:
>> + /* Slave transfer synchronized - mem to dev (TX) transfer */
>> + dev_dbg(uc->ud->dev, "%s: chan%d as MEM-to-DEV\n", __func__,
>> + uc->id);
>> +
>> + ret = udma_v2_alloc_tx_resources(uc);
>> + if (ret) {
>> + uc->config.remote_thread_id = -1;
>> + return ret;
>> + }
>> +
>> + uc->config.src_thread = ud->psil_base + uc->tchan->id;
>> + uc->config.dst_thread = uc->config.remote_thread_id;
>> + uc->config.dst_thread |= K3_PSIL_DST_THREAD_ID_OFFSET;
>> +
>> + irq_ring_idx = uc->config.mapped_channel_id;
>> + break;
>> + case DMA_DEV_TO_MEM:
>> + /* Slave transfer synchronized - dev to mem (RX) transfer */
>> + dev_dbg(uc->ud->dev, "%s: chan%d as DEV-to-MEM\n", __func__,
>> + uc->id);
>> +
>> + ret = udma_v2_alloc_rx_resources(uc);
>> + if (ret) {
>> + uc->config.remote_thread_id = -1;
>> + return ret;
>> + }
>> +
>> + uc->config.src_thread = uc->config.remote_thread_id;
>> + uc->config.dst_thread = (ud->psil_base + uc->rchan->id) |
>> + K3_PSIL_DST_THREAD_ID_OFFSET;
>> +
>> + irq_ring_idx = uc->config.mapped_channel_id;
>> + udma_write(uc->rflow->reg_rt, UDMA_RX_FLOWRT_RFA, BIT(28));
>> + break;
>> + default:
>> + /* Can not happen */
>> + dev_err(uc->ud->dev, "%s: chan%d invalid direction (%u)\n",
>> + __func__, uc->id, uc->config.dir);
>> + return -EINVAL;
>> + }
>> +
>> + /* check if the channel configuration was successful */
>> + if (ret)
>> + goto err_res_free;
>> +
>> + if (udma_is_chan_running(uc)) {
>> + dev_warn(ud->dev, "chan%d: is running!\n", uc->id);
>> + ud->reset_chan(uc, false);
>> + if (udma_is_chan_running(uc)) {
>> + dev_err(ud->dev, "chan%d: won't stop!\n", uc->id);
>> + ret = -EBUSY;
>> + goto err_res_free;
>> + }
>> + }
>> +
>> + uc->dma_dev = dmaengine_get_dma_device(chan);
>> + uc->hdesc_pool = dma_pool_create(uc->name, uc->dma_dev,
>> + uc->config.hdesc_size, ud->desc_align,
>> + 0);
>> + if (!uc->hdesc_pool) {
>> + dev_err(ud->ddev.dev,
>> + "Descriptor pool allocation failed\n");
>> + uc->use_dma_pool = false;
>> + ret = -ENOMEM;
>> + goto err_res_free;
>> + }
>> +
>> + uc->use_dma_pool = true;
>> +
>> + uc->psil_paired = true;
>> +
>> + INIT_DELAYED_WORK(&uc->tx_drain.work, udma_check_tx_completion);
>> +
>> + if (uc->config.dir == DMA_MEM_TO_DEV)
>> + snprintf(irq_name, sizeof(irq_name), "tx-%u", irq_ring_idx);
>> + else
>> + snprintf(irq_name, sizeof(irq_name), "rx-%u", irq_ring_idx);
>> + uc->irq_num_ring = platform_get_irq_byname(pdev, irq_name);
>> + if (uc->irq_num_ring < 0) {
>> + ret = uc->irq_num_ring;
>> + goto err_res_free;
>> + }
>> +
>> + ret = request_irq(uc->irq_num_ring, udma_v2_ring_irq_handler,
>> + IRQF_SHARED | IRQF_TRIGGER_HIGH, uc->name, uc);
>> +
>> + if (ret) {
>> + dev_err(ud->dev, "chan%d: ring irq request failed\n", uc->id);
>> + goto err_irq_free;
>> + }
>> +
>> + uc->irq_num_udma = 0;
>> +
>> + udma_reset_rings(uc);
>> +
>> + if (uc->tchan)
>> + dev_dbg(ud->dev,
>> + "chan%d: tchan%d, tflow%d, Remote thread: 0x%04x\n",
>> + uc->id, uc->tchan->id, uc->tchan->tflow_id,
>> + uc->config.remote_thread_id);
>> + else if (uc->rchan)
>> + dev_dbg(ud->dev,
>> + "chan%d: rchan%d, rflow%d, Remote thread: 0x%04x\n",
>> + uc->id, uc->rchan->id, uc->rflow->id,
>> + uc->config.remote_thread_id);
>> + return 0;
>> +
>> +err_irq_free:
>> + uc->irq_num_ring = 0;
>> +err_res_free:
>> + udma_free_tx_resources(uc);
>> + udma_free_rx_resources(uc);
>> +
>> + udma_reset_uchan(uc);
>> +
>> + if (uc->use_dma_pool) {
>> + dma_pool_destroy(uc->hdesc_pool);
>> + uc->use_dma_pool = false;
>> + }
>> +
>> + return ret;
>> +}
>> +
>> static enum dma_status udma_v2_tx_status(struct dma_chan *chan,
>> dma_cookie_t cookie,
>> struct dma_tx_state *txstate)
>> @@ -1032,11 +1174,34 @@ static struct udma_match_data bcdma_v2_am62l_data = {
>> .rchan_cnt = 128,
>> };
>>
>> +static struct udma_match_data pktdma_v2_am62l_data = {
>> + .type = DMA_TYPE_PKTDMA,
>> + .version = K3_UDMA_V2,
>> + .psil_base = 0x1000,
>> + .enable_memcpy_support = false, /* PKTDMA does not support MEM_TO_MEM */
>> + .flags = UDMA_FLAGS_J7_CLASS,
>> + .statictr_z_mask = GENMASK(23, 0),
>> + .burst_size = {
>> + TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_64_BYTES, /* Normal Channels */
>> + 0, /* No H Channels */
>> + 0, /* No UH Channels */
>> + },
>> + .tchan_cnt = 97,
>> + .rchan_cnt = 97,
>> + .chan_cnt = 97,
>> + .tflow_cnt = 112,
>> + .rflow_cnt = 112,
>> +};
>> +
>> static const struct of_device_id udma_of_match[] = {
>> {
>> .compatible = "ti,am62l-dmss-bcdma",
>> .data = &bcdma_v2_am62l_data,
>> },
>> + {
>> + .compatible = "ti,am62l-dmss-pktdma",
>> + .data = &pktdma_v2_am62l_data,
>> + },
>> { /* Sentinel */ },
>> };
>>
>> @@ -1055,15 +1220,23 @@ static int udma_v2_get_mmrs(struct platform_device *pdev, struct udma_dev *ud)
>> if (IS_ERR(ud->mmrs[V2_MMR_GCFG]))
>> return PTR_ERR(ud->mmrs[V2_MMR_GCFG]);
>>
>> - ud->bchan_cnt = ud->match_data->bchan_cnt;
>> - /* There are no tchan and rchan in BCDMA_V2.
>> + /* There are no tchan and rchan in BCDMA_V2 and PKTDMA_V2.
>> * Duplicate chan as tchan and rchan to keep the common code
>> - * in k3-udma-common.c functional for BCDMA_V2.
>> + * in k3-udma-common.c functional.
>> */
>> - ud->chan_cnt = ud->match_data->chan_cnt;
>> - ud->tchan_cnt = ud->match_data->chan_cnt;
>> - ud->rchan_cnt = ud->match_data->chan_cnt;
>> - ud->rflow_cnt = ud->chan_cnt;
>> + if (ud->match_data->type == DMA_TYPE_BCDMA) {
>> + ud->bchan_cnt = ud->match_data->bchan_cnt;
>> + ud->chan_cnt = ud->match_data->chan_cnt;
>> + ud->tchan_cnt = ud->match_data->chan_cnt;
>> + ud->rchan_cnt = ud->match_data->chan_cnt;
>> + ud->rflow_cnt = ud->chan_cnt;
>> + } else if (ud->match_data->type == DMA_TYPE_PKTDMA) {
>> + ud->chan_cnt = ud->match_data->chan_cnt;
>> + ud->tchan_cnt = ud->match_data->tchan_cnt;
>> + ud->rchan_cnt = ud->match_data->rchan_cnt;
>> + ud->tflow_cnt = ud->match_data->tflow_cnt;
>> + ud->rflow_cnt = ud->match_data->rflow_cnt;
>> + }
>>
>> for (i = 1; i < V2_MMR_LAST; i++) {
>> if (i == V2_MMR_BCHANRT && ud->bchan_cnt == 0)
>> @@ -1117,6 +1290,7 @@ static int udma_v2_probe(struct platform_device *pdev)
>> ud->reset_chan = udma_v2_reset_chan;
>> ud->decrement_byte_counters = udma_v2_decrement_byte_counters;
>> ud->bcdma_setup_sci_resources = NULL;
>> + ud->pktdma_setup_sci_resources = NULL;
>>
>> ret = udma_v2_get_mmrs(pdev, ud);
>> if (ret)
>> @@ -1124,7 +1298,17 @@ static int udma_v2_probe(struct platform_device *pdev)
>>
>> struct k3_ringacc_init_data ring_init_data = {0};
>>
>> - ring_init_data.num_rings = ud->bchan_cnt + ud->chan_cnt;
>> + if (ud->match_data->type == DMA_TYPE_BCDMA) {
>> + ring_init_data.num_rings = ud->bchan_cnt + ud->chan_cnt;
>> + } else if (ud->match_data->type == DMA_TYPE_PKTDMA) {
>> + ring_init_data.num_rings = ud->rflow_cnt;
> Hmm, how does this work? Shouldnt there be ring allocated for both tflow
> and rflow and hence tflow_cnt + rflow_cnt?
Vignesh, just like the channels, the flows are interleaved. So both
tflow_cnt
and rflow_cnt are set to the total flow cnt in case of V2.